[Feature]: OTLP File Exporter

[joshwlewis]

Related Problems?

Prior to #2040, the opentelemetry-stdout crate was able to export in a format compatible with the OTLP File Exporter specification here. Passing in a file as the writer allowed the exporter to export to a file, and the default JSON serializer was compatible with the spec (example setup here). Since #2040, a writer can no longer be passed in, and the format is not JSON.

Describe the solution you'd like:

I'd love to see a FileExporter that complies with https://opentelemetry.io/docs/specs/otel/protocol/file-exporter.

Considered Alternatives

No response

Additional Context

There is some discussion here about whether this functionality is strictly required for SDKs.

I may have to roll my own OTLP File Exporter soon. I could potentially contribute it back to this library if desired.

[cijothomas]

Happy to host it in the contrib repo. (Or even this repo.)
Feel free to send a PR.